Short on time but want to tone up all those trouble spots? We asked Danielle Natoni, a personal trainer and founder of Fit and Funky to create a strength training workout that works your entire body. Bonus—no equipment is necessary!

Muscle works

Courtesy Darren Natoni

When you build lean muscle mass (like doing this workout), you burn more calories—it’s that easy. In fact, the benefits of strength training are pretty impressive. How does it work? Muscle is metabolically active. “The more lean muscle mass you have the more calories you burn. Lean muscle requires more calories than fat does, so your metabolism revs up to help you burn those additional calories,” says Danielle Natoni, AFAA personal trainer and CEO and founder of Fit and Funky. “In addition, adding lean muscle through resistance training will strengthen your bones and improve your overall physical performance—not just in workouts, but everyday life activities,” says Natoni. Research also shows resistance training helps keep anxiety in check. Another study suggests strength training can improve insulin sensitivity, glucose tolerance, metabolic health, and even reducing risk factors for people with diabetes. There’s even evidence that long-term resistance training can prevent inflammatory chronic diseases. Here are 14 things that happen when you start a new strength-training workout.

No equipment needed!

Courtesy Darren Natoni

Women often skip strength training because they’re worried about bulking up or looking too muscular. Getting body-builder definition requires a special genetic mix that few people have—not to mention an otherworldly devotion to lifting and careful dieting.

If you have access to dumbbells, great. If not, don’t worry—you can accomplish all you need using your own body weight. “Your own body weight serves as an amazing way to do resistance training, especially when you are short on time or don’t have access to weights,” says Natoni. Using machines at the gym keeps you in a stationary position and usually targets just a couple of areas, she warns. That’s effective, but when you use your own body for resistance, you target numerous muscle groups at the same time. For instance, a plank builds muscles along the spine, in your rear, and challenges your core—the abdomen, chest, and upper legs! Relying on your body to build muscles improves your flexibility and balance as well, explains Natoni.

Natoni’s 15-minute workout targets all areas of the body. “Do each move for one minute,” she says. “At the end of the circuit, take a one-minute break and then repeat the circuit one more time for a total of 15 minutes. Focus on form over speed to really fatigue the muscles and get in a good burn.”

Squat to lunge

Courtesy Darren Natoni

Start with your feet about hip distance apart and lower into a squat, weight on your heels and your back flat; clasp your hands in front of your chest for balance. From the bottom of the squat, jump up while bringing your right leg forward and left leg back into a lunge. Be sure to land softly. In the lunge, make sure your knees are creating two 90 degree angles, and that the ears, shoulders, and hips are stacked on top of each other. From the bottom of the lunge, explode back up and land into the squat. Repeat with the right leg coming forward for the entire minute. Minute two of the workout you’ll switch to your left leg coming forward into the lunge. For a less-demanding version, simply step the leg back into the lunge instead of jumping. Also, you can reduce your range of motion by not going as deep into the squat or the lunge. This is how many squats it takes to see results.

Plank shoulder taps

Courtesy Darren Natoni

Get into a plank by supporting yourself on your hands and toes—hands directly underneath your shoulders. Your hips should be square to the ground, back flat, head, neck, and butt aligned to keep your spine neutral. For balance, you can keep your feet about shoulder-width apart. Shift your weight to your left side and slowly bring your right arm up to your left shoulder and then back down. Repeat with your left arm. Take a one-second pause in each movement. Go for one minute alternating back and forth between sides. To modify this movement, simply drop into a knees-down plank and keep the arm movements the same.

Tricep dips

Courtesy Darren Natoni

Sit on the ground with your heels on the floor, and place your hands slightly behind your bottom, your fingers pointing the same direction as your toes. Press your shoulders back and down from the ears, raising your butt up off the ground by pressing your body weight into your triceps. Now, lower your bottom towards the ground, getting close to the ground without touching. As you lower, bend your elbows and make sure they point directly behind you and that your shoulders stay pressed away from the ears. Lift back up; repeat for the entire minute. To modify this move, you can reduce the range of motion by not going down as deep, or you can set your bottom on the ground and press your forearms toward the ground by leaning back slightly. Here are 8 health problems that can be improved with strength training.

Bow and Arrow

Courtesy Darren Natoni

Lie face down on the ground and extend your legs back and up off the ground by squeezing through your glutes. Keep your head aligned with your spine as you extend your arms out in front of you and bring your hands together. Lift your chest off the ground by engaging the muscles in your lower back. Now, draw your arms toward the right side of your body, drawing your right elbow towards your ribs. Return to the starting position. Repeat on the right side for one full minute, then do a minute on the left side. To modify this movement, only lift the upper body and drive your toes into the ground to give the lower back support.

Wall sit

Courtesy Darren Natoni

Lean back against a wall and slide down into a sitting position, with your knees and hips at 90-degree angles. Raise your arms straight up overhead and press your thumbs into the wall. Pause for one second, and then press up onto your toes while lowering your arms to your sides in a “T,” pinkies against the wall. Pause for one second, and then lower your heels while raising your arms back up. Repeat for one minute. To modify this movement, reduce the range of motion in the squat or remove the arm movement so you can focus your efforts on the lower body. Next, check out these 6 at-home workouts to lose weight and build muscle.